The batch anaerobic fermentation at medium temperature( 37 ± 1℃) using physical treated banana pseudo stem samples with fiber length of 0.23,2.70,4.10 and 4.12 cm was conducted.The influence of physical treatment on anaerobic fermentation of banana pseudo stem and its feasibility for mass production of biogas was investigated.Results showed that increasing the strength of physical treatment could enhance the cumulative and daily biogas production of banana pseudo stem during biogas fermentation whereas have no significant impact on the methane concentration( between 55.54 % and 63.88 %).Samples with 0.23 and 2.79 cm fiber length obtained the highest daily biogas production of 333.6 and 319.8 mL/d,and the biogas yield of 306.49 and 340.13 mL/g VSadded,which were 32.11% ~ 34.92% and 8.29% ~ 17.36% higher than those of the 4.10 cm and 4.12 cm samples,respectively.Banana pseudo stem was recognized as a prospective material for producing biogas compared with wheat straw or corn straw.